Ernest k



(No Model.)

E. K. ADAMS. COMPBNSATING PBNDULUM.,

Patented Nov. 30,1897.

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Arrow/fm` UNITED STATES PATENT @Prion ERNEST K. ADAMS, 0F NEW YORK, N. Y.

COMPNSATNG PENULUWI.

SPECIFICATION forming part of Letters Patent No. 594,365, dated November 30, 1897.

Application led March 1 9 l 8 9 '7.

T0 all whom it may concern:

Beit known that I, ERNEST K. ADAMS, a citizen of the United States,residin g at New York, in the county and State of New York, have invented certain new and useful Improvements in Compensating Pendulums, of which the following is a specification, reference being had to the drawings accompanying and forming a part of the same.

The object of my invention is to provide a device for use with pendulums which shall compensate for variations in the length of the latter, due to changes of temperature, by varying the distance between the point of suspension and the center of oscillation.

It has heretofore been proposed to preserve uniform the effective length of a pendulum, subject to elongation and contraction under variations of temperature, both by shifting the center of suspension with reference to a fixed point of support and shifting the point of support with reference to a fixed center of suspension, this being effected, among other ways, by attaching the iieXible end of the pendulum at a given point to the clock-frame and employing a standard of metal of high coefficient of expansion secured at one end to the clock-frame and carrying at the other a slotted stud embracing the flexible portion of the pendulum and forming the center of suspension therefor, or by suspending the pendulum from the expansible standard and securing the slotted stud to the clock-frame.

My invention is a device of this general character, but it is an improvement on those heretofore made mainly in the following` particulars: In the previous devices of this character either the center of suspension or the point of support for the pendulum occupied a position intermediate to the ends of the eXpansible standard and independent thereof, and as a consequence the expansion and contraction of the clock-frame or supports for the standard itself played a part in determining the effective length of the pendulum, and thus introduced an element of error which there was no means of correcting or providing against. This objection I avoid by arranging the two points mentioned at opposite ends of the eXpansible standard, so that they will always exactly accord in position with the ends of the standard. To suc- Serial No. 628,272. (No model.)

cessfully accomplish this, I employ an eX- pansible standard of hard rubber in lieu of the metal heretofore employed, and I make 'the standard in cylindrical form and provide of a torsional pendulum; and Figs. 5 and 6,

plan and sectional views, respectively, of a slotted plate through which the iiexible portion of the pendulum passes.

F designates the supporting plate or frame which carries the pendulum and which is formed or provided with a lateral bracket or platform F. Mounted on the latter is the expansible standard, which is composed of vulcanite or hard rubber and preferably adjustable in length by being `made in three parts-a main cylinder R2, a shorter cylindrical section R', and a coupling-sleeve R3. The section R and sleeve R3 are threaded, the former being secured against rotation by pins T set in the part R2 and entering holes in the part It, so that by turning the sleeve R3 to the right or the left varies t-he total height of the standard.

The pendulum is of any usual construction, but comprises a flexible strap or band S of somewhat greater length than the expansible standard. The remaining parts may be of any ordinary construction, that shown in Fig. 2 consisting of a wooden rod B and a bob B. The upper end of the strap S is suspended from a cross-bar P, resting in notches in the top of the expansible cylinder or standard, and the strap passes through a slot in a plate D, secured to the lower end of the cylinder or to the platform to which the latter is fixed, and at its end.

The length or height of the expansible cylinder is calculated with reference to the predetermined or calculable rate of expansion and contraction of the pendulum by a wellunderstood formula, the coefficient of expan- IOO sion of the material comprising the cylinder being knowmso that variations in length of the pendulum will be compensated for by the correspondingly greater variations in the height of the cylinder and the effective length of the pendulum maintained uniform by the raising or lowering of its point of support. A similar effect will be secured in the case of a torsional pendulum, such as shown in Figs. 3 and 4f, by forming the opening in the plate D and that portion of the wire S which passes through it in such manner that the latter is prevented from twisting at that point.

By making the eXpansible standard in the form of a cylinder it is possible tovcalculate in advance and to a nicety the length required, while the exact alinement of the point of support and center of suspension are much more nearly preserved than by other forms.

The two forms of pendulum shown-viz., the oscillating and torsionalare evidently equivalents for the purposes of this case, although the same descriptive terms used in the claims may not strictly apply to both. I may also apply the principle of my invention to other forms of pendulum, and I may vary the construction of the parts shown in many ways. For example, in lieu of the slotted or perforated plate D, l may employ any device which performs the same office.

Having now described my invention, what l claim is l. The combination with a pendulum, of a support thereforconsisting of astandard composed of a material having a coeflicient of expansion higher than that of the pendulum, and a device constituting a center of suspension secured at one end of the standard, the pendulum being supported from a point at the opposite end of the standard and passing through the center of suspension, whereby the effective length of the pendulum will be maintained uniform by the expansion and contraction of the standard and consequent variation of the distance between the point of support and center of suspension, as set forth.

2. rlhe combination with a pendulun'i, of a cylinder composed of a material havinga co efficient of expansion higher than that of the pendulum, a support at one end of the cylinder to which the pendulum. is attached, and a device, such as a slotted plate, which forms a center of suspension at the opposite end of the cylinder and through which the pendulum passes.

The combination with a pendulum, of a cylinder of hard rubber, a support at one end of the cylinder to which the pendulum is attached, and a slotted plate at the other which -forms a center of suspension through which the pendulum passes.

it. The combination with a pendulum of a support composed of a cylinder of highly-expansible material, the pendulum being supported at one end of said cylinder and passing through a contracted opening at the other, the said cylinder being formed in sections adjustable with reference to each other,\\'l1ercby its length or height may be varied, as set forth.

ERNEST lil. ADAMS. lVitnesscs:

M. Lawson Dyna, G. l. Lnwrs. 

